ctg(П/2) + tg П - sin (2/3П) -cos (-П/2)+sinП

πctg(π/2)=0;    tgπ=0;  sin(2π/3)=sin(π-π/3)=sin(π/3)=√3/2;

cos(-π/2)=cos(π/2)=0;   sinπ=0

Значит, 0 + 0 - √3/2 - 0 + 0 = -√3/2